The present invention relates generally to umbrellas, and more particularly, is directed to a collapsible umbrella with a reinforced rib structure.
Compact foldable umbrellas are known which include a telescoping center post with a handle secured to the lower end thereof, the handle being adapted to be grasped by a user to carry the umbrella in its stored configuration and to hold the umbrella in its raised, opened configuration. A stationary hub is secured at the upper end of the center post, with a canopy centrally secured to the stationary hub, and a sleeve is slidably mounted on the telescoping post.
A plurality of equiangularly spaced, radially directed ribs are secured to the canopy in equiangularly spaced relation, each rib having a radially inward end and a radially outward end.
A plurality of strut assemblies are provided, each connected between the sleeve and a respective rib. Each strut assembly includes a first strut having one end pivotally connected at a first pivot point to the sleeve and a second end pivotally connected to a rib at a second pivot point spaced slightly radially outward from the radially inward end of the rib. A second strut has one end pivotally connected at a third pivot point to the stationary hub and a second end pivotally connected at a fourth pivot point to an intermediate point of the first strut, and a third strut has one end pivotally connected at a fifth pivot point to an intermediate point of the second strut and a second end pivotally connected at a sixth pivot point to the respective one of the ribs, the sixth pivot point being positioned radially inward of the second pivot point.
However, a problem with such arrangement is that, during high winds, the forces on the canopy may invert the canopy, rendering the umbrella useless. Specifically, the first strut will pivot relative to the rib about the second pivot point such that the first strut moves to a position adjacent the sixth pivot point. In such case, there is nothing to stop the inversion of the umbrella. As a result, the first strut continues pivoting upwardly relative to the sleeve about the first pivot point, resulting in inversion of the umbrella.
Although various umbrellas are known which include channels for receiving strut members, these channels are not arranged relative to the ribs with the channel facing toward the ribs in a direction to prevent inversion of the umbrella. As a result, such channels will not prevent an upward inversion of the ribs, for example when the umbrella is subjected to high wind forces.